Non-linear single axis navigation sensor with strain relief

Abstract

The distal end of the catheter can be constructed to include one or more features to provide strain relief to wiring of multiple single axis sensors. In some examples, the multiple single axis sensors and associated wiring can be manufactured over a flexible tube that can be placed over a movable support member. In some examples, wiring can be wound an increased number of consecutive traverse turns on a distal and/or proximal side of a single axis sensor, and a shrink sleeve may be positioned over the traverse turns. In some examples a wire shield transition point can be positioned on a straight portion in a proximal direction to the distal portion of the catheter.

What is claimed is: 
     
       1. A single axis sensor (SAS) assembly comprising:
 a tubular member comprising a lumen therethrough sized to receive an elongated support member suitable for shaping a distal section of a mapping catheter; 
 a distal inductive coil affixed to the tubular member and coaxial to the tubular member and comprising leads; 
 a first dual cable electrically joined to the leads of the distal inductive coil and wound over the tubular member and an elbow of the distal section of the mapping catheter; 
 a proximal inductive coil affixed to the tubular member across the first dual cable, coaxial to the tubular member, and separated from the distal inductive coil such that the distal inductive coil moves in relation to the proximal inductive coil when the tubular member is moved from a linear configuration to a nonlinear configuration; and 
 an intermediate inductive coil affixed to the tubular member, coaxial to the tubular member, positioned between the distal inductive coil and the proximal inductive coil when the SAS assembly is in the linear configuration, the first dual cable being wound over a distal end of a first protective tube, the first protective tube covering the intermediate inductive coil. 
 
     
     
       2. The SAS assembly of  claim 1 , the nonlinear configuration being approximately circular with a circumference measuring from 24 millimeters 96 millimeters. 
     
     
       3. The SAS assembly of  claim 1 , the lumen comprising a diameter measuring from 0.08 mm to 0.3 mm. 
     
     
       4. The SAS assembly of  claim 1 , further comprising:
 a second dual cable electrically joined to leads of the intermediate inductive coil and wound over the tubular member to cross the proximal inductive coil. 
 
     
     
       5. The SAS assembly of  claim 1 ,
 the nonlinear configuration being circular, and 
 the proximal inductive coil, intermediate inductive coil, and distal inductive coil being positioned equidistant around a circumference of the nonlinear configuration. 
 
     
     
       6. The SAS assembly of  claim 1 , the first dual cable being wound for 5 to 7 consecutive traverse turns of 720° around the first protective tube covering the intermediate inductive coil and the tubular member adjacent the distal end of the intermediate inductive coil. 
     
     
       7. The SAS assembly of  claim 6 , further comprising:
 a second protective tube positioned to completely cover the traverse turns. 
 
     
     
       8. The SAS assembly of  claim 1 , the elbow comprising a diameter of 0.18 inches to 0.26 inches. 
     
     
       9. The SAS assembly of  claim 1 , further comprising a shrink sleeve extending over the length of the SAS assembly. 
     
     
       10. The SAS assembly of  claim 8 , further comprising:
 a shield wire transition point positioned on a straight region of the elongated support member and away from the elbow, the straight region maintaining a straight configuration when the elongated support member moves to the nonlinear configuration. 
 
     
     
       11. A mapping catheter comprising:
 an elongated support member extending through a distal section of the mapping catheter and comprising a nonlinear predetermined configuration to which the elongated support member moves when the distal section is disposed within a patient; and 
 a single axis sensor (SAS) assembly comprising:
 a tubular member surrounding the elongated support member, 
 a distal inductive coil affixed to the tubular member and coaxial to the tubular member, 
 a proximal inductive coil affixed to the tubular member, coaxial to the tubular member, and separated from the distal inductive coil such that the distal inductive coil moves in relation to the proximal inductive coil when the elongated support member moves to the nonlinear predetermined configuration, 
 a first dual cable electrically joined to leads of the distal inductive coil and wound over the tubular member to cross the proximal inductive coil, the first dual cable further being wound about an elbow of the distal section of the mapping catheter; and 
 an intermediate inductive coil affixed to the tubular member, coaxial to the tubular member, positioned between the distal inductive coil and the proximal inductive coil when the elongated support member is linearly elongated, the first dual cable being wound over a distal end of a first protective tube, the first protective tube covering the intermediate inductive coil. 
 
 
     
     
       12. The mapping catheter of  claim 11 , the intermediate inductive coil positioned such that the proximal inductive coil, intermediate inductive coil, and distal inductive coil collectively function as a three-axis sensor when the elongated support member moves to the nonlinear predetermined configuration. 
     
     
       13. The mapping catheter of  claim 12 ,
 the nonlinear predetermined configuration being circular, and 
 the proximal inductive coil, intermediate inductive coil, and distal inductive coil being positioned equidistant around a circumference of the nonlinear predetermined configuration. 
 
     
     
       14. The mapping catheter of  claim 13 , the nonlinear predetermined configuration comprising a circumference measuring from 10 millimeters to 50 millimeters. 
     
     
       15. The mapping catheter of  claim 12 , the SAS assembly further comprising:
 a second dual cable electrically joined to leads of the intermediate inductive coil and wound over the tubular member to cross the proximal inductive coil. 
 
     
     
       16. The mapping catheter of  claim 12 , the first dual cable being wound for 5 to 7 consecutive traverse turns of 720° around the first protective tube covering the intermediate inductive coil and the tubular member adjacent the distal end the tubular member adjacent a side of the respective coil. 
     
     
       17. The mapping catheter of  claim 16 , the SAS further comprising a second protective tube positioned to completely cover the traverse turns. 
     
     
       18. The mapping catheter of  claim 11 , the elongated support member comprising a memory shape material heat set to the nonlinear predetermined configuration.